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Don Rey Guest
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Serial EEPROM problem |
Posted: Fri Nov 19, 2004 2:15 pm |
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I'm working with Serial EEPROM PIC24L256, I fist store different values in differents memory address, then i read each values for each memory address. My problem is when I read this values they are differents to the values stored.
This my code
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#include <16F873.H>
#include <stdio.h>
#use delay(clock=4000000)
#use rs232(baud=9600,bits=8,parity=N,xmit=PIN_C6,rcv=PIN_C7,BRGH1OK)
#use i2c(master,sda=PIN_C4, scl=PIN_C3)
#define hi(x) (*(&x+1))
#byte PORTA = 0x05
#byte PORTC = 0x07
#byte PORTB = 0x06
#byte RTCC = 0x01
//****************************************************Rutinas del EEPROM I2C*********************************************************
void write_ext_eeprom(long int address, byte data)
{
i2c_start();
i2c_write(0xa0);
i2c_write(hi(address)&0x7f); //Storage until 32K
i2c_write(address);
i2c_write(data);
i2c_stop();
delay_ms(35);
}
byte read_ext_eeprom(long int address) {
byte data;
i2c_start();
i2c_write(0xa0);
i2c_write(hi(address)&0x7f); //Reading until 32K
i2c_write(address);
i2c_start();
i2c_write(0xa1);
data=i2c_read(0);
i2c_stop();
return(data);
}
//**************************************************Rutina de Lectura del A/D*********************************************************
unsigned ReadADC(unsigned chn){
SET_ADC_CHANNEL(chn);
DELAY_CYCLES(32);
return READ_ADC();
}
unsigned ADCchannel(unsigned ch)
{
switch(ch) {
case 0:
BIT_CLEAR(PORTB,5);
BIT_CLEAR(PORTB,6);
BIT_CLEAR(PORTB,7);
break;
case 1:
BIT_SET(PORTB,5);
BIT_CLEAR(PORTB,6);
BIT_CLEAR(PORTB,7);
break;
case 2:
BIT_CLEAR(PORTB,5);
BIT_SET(PORTB,6);
BIT_CLEAR(PORTB,7);
break;
case 3:
BIT_SET(PORTB,5);
BIT_SET(PORTB,6);
BIT_CLEAR(PORTB,7);
break;
case 4:
BIT_CLEAR(PORTB,5);
BIT_CLEAR(PORTB,6);
BIT_SET(PORTB,7);
break;
case 5:
BIT_SET(PORTB,5);
BIT_CLEAR(PORTB,6);
BIT_SET(PORTB,7);
break;
case 6:
BIT_CLEAR(PORTB,5);
BIT_SET(PORTB,6);
BIT_SET(PORTB,7);
break;
case 7:
BIT_SET(PORTB,5);
BIT_SET(PORTB,6);
BIT_SET(PORTB,7);
break; }
}
//*************************************************Inicio del Main*********************************************************************
main() {
int dat,yi, addr[50], j;
byte start;
//OUTPUT_HIGH(PIN_B1);
puts("Iniciando Adquisición de Datos");
set_tris_a (0xFF); // puerto A todo entrada
set_tris_b (0x03); // RB0(ext int) entrada y RB1, el resto salidas
set_rtcc(0);
setup_counters( RTCC_INTERNAL, RTCC_DIV_256);
enable_interrupts(RTCC_ZERO);
enable_interrupts(GLOBAL);
setup_port_a( ALL_ANALOG );
setup_adc( ADC_CLOCK_INTERNAL );
enable_interrupts(int_rda);
do {
for(j=2; j<=7; ++j)
{
ADCchannel(0);
SET_ADC_CHANNEL(0);
DELAY_CYCLES(32);
yi=READ_ADC();
printf("\n\rValor numero %d ADC Canal_0: %2X \r\n",j,yi); //Valor de RA0 en la prueba
write_ext_eeprom(addr[j],yi);
delay_ms(2000); }
printf("\nValores almacenados en EEPROM I2C\n");
for(j=0; j<=5; j++)
{
dat=read_ext_eeprom(addr[j]);
printf("\n\rValor Número %d almacenado canal 1: %2X \r\n",j,dat);
delay_ms(500);
}
printf("\n prueba finalizada \n");
}
while(true);
} |
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PCM programmer
Joined: 06 Sep 2003 Posts: 21708
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Posted: Fri Nov 19, 2004 3:21 pm |
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I'm going to assume that you don't really intend to get your eeprom
addresses from an array. So I suggest the following:
These two lines are wrong:
Quote: | write_ext_eeprom(addr[j],yi);
dat=read_ext_eeprom(addr[j]); |
Change them to this:
Code: | write_ext_eeprom(j, yi);
dat=read_ext_eeprom(j); |
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ckielstra
Joined: 18 Mar 2004 Posts: 3680 Location: The Netherlands
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Posted: Fri Nov 19, 2004 6:36 pm |
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Quote: | I'm working with Serial EEPROM PIC24L256 |
I can't find info on this chip. Do you mean the PIC24LC256?
If yes, then you can optimize your write speed by decreasing the delay_ms(35) to delay_ms(5).
Also see the other thread on the PIC24FC515 that is going on today for another code example, click here. |
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Mark
Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA
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Posted: Fri Nov 19, 2004 10:07 pm |
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Quote: | If yes, then you can optimize your write speed by decreasing the delay_ms(35) to delay_ms(5).
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The is the wrong way of doing it. You should look for an acknowledgement when addressing the device. If it busy, say writing, you will not get the ack. There is no need for a delay and is a more efficient approach. |
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Don Rey Guest
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Posted: Sat Nov 20, 2004 6:56 am |
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Thanks to all,
I changed from:
write_ext_eeprom(addr[j],yi);
dat=read_ext_eeprom(addr[j]);
to:
write_ext_eeprom(j, yi);
dat=read_ext_eeprom(j);
Apperently I was writting to a memory space without be define
Thanks |
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